Outlook and outcome – December 2001 to February 2002

Parts of the southwest of the South Island experienced the predicted below average rainfall. Central New Zealand and eastern North Island regions received more rain than was predicted. There was near average seasonal rainfall elsewhere as expected.

The anticipated average to above average temperatures were experienced over much of the country. The exceptions were a few eastern regions where conditions were cooler than expected.

River flows were expected to be normal to above normal in northern New Zealand and below normal in the southwest. Summer flows were mostly above normal, except in south Westland and Southland.

The outcome maps shown here give the tercile rankings of the rainfall totals and mean temperatures that eventuated for these months. Terciles were obtained by dividing ranked December to February data from the past 30 years into three groups of equal frequency (lower, middle and upper one-third values) and assigning the data for the present year to the appropriate group. (Click to enlarge)

As an approximate guide, middle tercile rainfalls often range from 80 to 115% of the historical average. Middle tercile air temperatures typically occur in the range of the average plus or minus 0.5°C.